Dual direction bypass valve

ABSTRACT

A dual direction bypass valve allows a transmission filter to function whether or not it is placed in the vehicle transmission correctly. The filter includes a front and rear valve bodies separated by an end cap, and each having a spring and disk. When the filter media is clogged during normal forward flow, the fluid pressure on the rear valve body disk compresses the spring, opening an aperture in the end cap, allowing the fluid to pass from the front valve body through the rear valve body to the outlet, bypassing the filter media. If the transmission filter is placed in the engine backwards, the fluid pressure compresses the spring of the front valve body and opens up apertures in the end cap, such that the fluid flows through the apertures and the front valve body, bypassing the rear valve body and the filter media, to exit the filter.

FIELD OF THE INVENTION

[0001] The present invention relates to the field of bypass valves forfluid filters. In particular, the present invention is related to abypass valve for a transmission filter for a vehicle with automatictransmission, which allows transmission fluid to flow in oppositedirections through the filter.

BACKGROUND OF THE INVENTION

[0002] Transmission fluid in vehicles with automatic transmissions, iscirculated through a filter to remove particles that may damagemechanical components of the transmission. These particles may includemetal particles that can be particularly damaging to the transmissioncomponents.

[0003] A prior art transmission fluid filter 10, such as thetransmission filter disclosed in U.S. Pat. No. 6,139,737 (Gizowski),includes such a conventional bypass valve 11 in housing 23 (see FIG. 1).The bypass valve 11 includes a tubular valve body 12 attached to, andaxially extending from the distal end of post 13. The valve 11 furtherincludes a plunger 14 which is slidably received in the valve body 12,and plunger spring 15 is received in valve body 12 between post 13 andplunger 14. Retainer 16 (which is integrally molded with the upper body17), is positioned between bypass valve 11 and inlet end wall 18, andretainer spring 19 attaches retainer 16 to end wall 18. If filter media20 becomes plugged during use of filter 10, the differential pressurebetween inlet 21 and outlet 22 overcomes the bias of the plunger spring15, shifting plunger 14 toward post 13. This allows fluid to passthrough valve body 12 into post 13, thereby bypassing filter media 20.Thus, although the fluid is not filtered, it does not clog the filter 20and result in overheating of the transmission.

[0004] However, Gizowski and other conventional transmission filterssuffer from the disadvantage that, since the inlet end 21 and outlet end22 are similar in appearance, if the filter 10 is placed in thetransmission of the vehicle backwards (i.e., fluid entering throughoutlet 22 and exiting through inlet 21), then a clog occurs, whichrestricts the flow of transmission fluid through the filter 10 resultingin the vehicle transmission overheating and causing damage to thevehicle transmission.

SUMMARY OF THE INVENTION

[0005] Accordingly, an object of the present invention is to provide adual direction bypass valve which allows the transmission filter tofunction whether or not it is placed in the vehicle transmissioncorrectly. In other words, even if the transmission filter is installedbackwards, the transmission filter will still function, fluid will stillgo through the filter, and damage will not be caused to the vehicletransmission.

[0006] The dual direction bypass valve for the transmission filterincludes a valve body having a front and a rear separated by a metal endcap. The front valve body includes a first metal spring seated over anaperture and against a round, preferably plastic, first disk. The firstspring and first disk are retained in a preferably metal, first springand disk retainer. Two substantially semi-circular holes are disposed inthe retainer on opposite sides from one another, and allow fluid to passthrough the holes. The front valve body allows fluid flow from theinlet, through an aperture in the first spring and disk retainer intothe first spring and disk retainer, and out through the retainer holes,towards the sides of the canister housing, and through spaces betweenthe central wall and the filter media. The fluid is then filtered by thefilter media, before collecting in a central passage in the filter, andexiting through the outlet.

[0007] The filter rear valve body includes a preferably metal, secondspring and disk retainer, which retains a second metal spring and asecond, round, phenolic (plastic) disk. An aperture and twosemi-circular holes in the second retainer, allow fluid to pass throughinto the second retainer when the dual direction bypass valve isdisposed backwards in the transmission. The semi-circular holes aredisposed opposite to one another. Two circular holes in the end capwhich is disposed between the first disk and the second disk, allowfluid to pass through the metal end cap from the central passage throughthe first retainer, when the dual direction bypass valve is disposedbackwards in the transmission.

[0008] During normal forward flow, the fluid enters through the inlet,the first retainer, around the sides of the canister, through the filtermedia to the central passage, and out through the outlet of the filter.

[0009] However, in normal forward flow bypass mode, when the filtermedia is clogged, the pressure of the fluid builds up against the seconddisk, and the fluid pressure forces the second disk to compress thesecond spring, allowing fluid to pass from the first retainer throughthe apertures in the first disk and the end cap, to the second retainerand through the filter central passage to the outlet.

[0010] When the dual direction transmission filter assembly ismistakenly inserted backwards in the vehicle transmission, in backwardsor reverse flow, the fluid enters through the outlet and passes throughthe filter central passage, through the filter media, and out throughthe first retainer and the inlet.

[0011] However, in backward or reverse flow bypass mode, if the filtermedia becomes clogged, the pressure of the fluid builds up against thefirst disk, forcing the first disk to compress the first spring, andallowing the fluid to pass through holes in the end cap of the filterand through the first retainer and out through the filter inlet.

[0012] Thus, the transmission is never damaged due to clogging of thefilter, even if the filter is inserted backwards in the transmission.

[0013] There has thus been outlined, rather broadly, the more importantfeatures of the invention in order that the detailed description thereofthat follows may be better understood, and in order that the presentcontribution to the art may be better appreciated. There are, of course,additional features of the invention that will be described below andwhich will form the subject matter of the claims appended hereto.

[0014] In this respect, before explaining at least one embodiment of theinvention in detail, it is to be understood that the invention is notlimited in its application to the details of construction and to thearrangements of the components set forth in the following description orillustrated in the drawings. The invention is capable of otherembodiments and of being practiced and carried out in various ways.Also, it is to be understood that the phraseology and terminologyemployed herein, as well as the abstract included below, are for thepurpose of description and should not be regarded as limiting.

[0015] As such, those skilled in the art will appreciate that theconception upon which this disclosure is based may readily be utilizedas a basis for the designing of other structures, methods and systemsfor carrying out the several purposes of the present invention. It isimportant, therefore, that the claims be regarded as including suchequivalent constructions insofar as they do not depart from the spiritand scope of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Additional features, details, and advantages of the invention,will become evident from the following description and the drawing,wherein:

[0017]FIG. 1 is a sectional view of a conventional filter;

[0018]FIG. 2 is a side view of the dual direction bypass filter inaccordance with one preferred embodiment of the present invention.

[0019]FIG. 3 is a sectional view of the dual direction bypass filtertaken along line 2-2 of FIG. 2, particularly showing the normal forwardflow of the fluid through the filter;

[0020]FIG. 4 is a detailed enlarged sectional view of the dual directionbypass filter of FIG. 3, particularly showing the normal forward flow ofthe fluid through the filter;

[0021]FIG. 5 is a detailed enlarged section view of the dual directionbypass filter of FIG. 3, particularly showing the second diskcompressing the second spring to allow fluid to bypass a clogged filtermedia during normal forward flow bypass mode;

[0022]FIG. 6 is a detailed enlarged sectional view of the dual directionbypass filter of FIG. 3, particularly showing the backward or reverseflow of the fluid through the filter;

[0023]FIG. 7 is a detailed enlarged sectional view of the dual directionbypass filter according to FIG. 3, particularly showing the first diskcompressing the first spring to allow fluid to bypass a clogged filtermedia during backward or reverse flow bypass mode; and

[0024]FIG. 8 is an enlarged view of the encircled area shown in FIG. 3,showing further detail of the dual direction bypass filter.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] The transmission filter 100 of the present invention, isdisclosed in the following description and shown in FIGS. 2-8. Thetransmission filter 100 (see FIG. 2), in accordance with a preferredembodiment of the present invention, includes a canister housing 101,filter media 102, and dual direction bypass valve 103.

[0026] The canister housing 101 (see FIG. 2) is composed of a metal orplastic material which is sturdy and able to withstand hightemperatures. The canister housing 101 includes an upper body 104 and alower body 105 which are joined by an ultrasonic weld. The upper body104 integrally includes inlet end wall 106 with tubular hose barb 107extending therefrom defining transmission fluid inlet 108 (see FIG. 3).The hose barb 107 is inserted onto a transmission hose (not shown) andclamped.

[0027] The lower body 105 of the canister housing 101 includes outletend wall 109 which is formed as an end cap, with another tubular hosebarb 110 extending therefrom defining transmission fluid outlet 111 (seeFIG. 3). The lower body 105 also includes a tubular central wall 112extending from outlet end wall 109 adjacent hose barb 110 to the inletend wall 106. An ultrasonic weld 113 joins the end cap 118 of outlet endwall 109 to central wall 112 as illustrated. Chamber 114 is formedwithin canister housing 101 between inlet 108 and outlet 111.

[0028] Filter media 102, which is made of a paper-based material or thelike, is received in chamber 104 in the fluid flow path (see arrowsshowing fluid flow direction in FIG. 3) between inlet 108 and outlet111. Filter media 102 surrounds a central passage 115 which extends fromthe inlet 108 to the outlet 111, and is spaced from the interior face116 of the central wall 112.

[0029] Inlet media end cap 117 and outlet media element end cap 118retain the filter media 102 in the position shown in FIG. 3. The inletmedia end cap 117 and outlet media end cap 118 are preferably made ofmetal. Seal 119, which is preferably composed of polyacrylate rubber, ispositioned between outlet end cap 118 and outlet end wall 109 to providea seal therebetween.

[0030] The dual direction bypass valve 103 includes a valve body 120having a front valve body 121 and a rear valve body 122 (see FIGS. 3-7).Inlet media end cap 117, which has a central hole 138 therein, separatesthe front valve body 121 and rear valve body 122.

[0031] Front valve body 121 (see FIG. 4) includes a first metal spring124 seated over an aperture 125 in a round, preferably plastic, firstdisk 126, the first spring 124 and first disk 126 both being retained ina preferably metal, first spring and disk retainer 128. The first disk126 is seated against end cap 117. (Note: Although the first disk 126 isseated against end cap 117, the Figures show some spacing for betterclarity). Two substantially semi-circular holes 123 are disposed in theretainer 128 on opposite sides from one another, and allow fluid to passthrough the holes 123. The front valve body 121 allows fluid flowthrough aperture 127 into the first retainer 128, and through the holes123, outwards, towards the sides of the canister housing 101 (see arrowsshowing direction of fluid flow in FIG. 3) and spaces 136 between thecentral wall 112 and the filter media 102.

[0032] Rear valve body 122 (see FIG. 4) includes a preferably metal,second spring and disk retainer 130, which retains a second metal spring131 and a second, round, phenolic (plastic) disk 129. Second disk 129 isseated against end cap 117, sealing the hole 138 in end cap 117. Anaperture 132, and two semi-circular holes 134 in the second retainer130, allow fluid to pass through into the second retainer 130 when thedual direction bypass valve 103 is disposed backwards in thetransmission. The semi-circular holes 134 are disposed opposite to oneanother. Two circular holes in end cap 117 allow fluid to pass throughthe metal end cap 117 from the central passage 115 through the firstretainer 128, when the dual direction bypass valve is disposed backwardsin the transmission.

[0033] A stabilizing metal spring 135 is disposed on first retainer 128,over aperture 127, to keep the valve body 120 seated firmly within thecanister 101 at the inlet end wall 106.

[0034] In operation, with the filter 100 correctly installed in theengine transmission, normal forward flow (see FIGS. 3-4) allowstransmission fluid to enter through inlet 108 and pass through spring135 and through aperture 127 into first retainer 128.

[0035] Circular shaped, flat phenolic second disk 129 is sealed againstend cap 117, preventing fluid from flowing through aperture 125 in thefirst disk 126. First disk 126 is also sealed against end cap 117,covering holes 133 and preventing any fluid from flowing therethrough.Accordingly, the fluid entering into the first retainer 128 then passesthrough apertures 123 and into space 136 between the interior face 116of the central wall 112 and the filter media 102.

[0036] An optional magnet 137 is positioned around the side wall of theinterior face 116 of the filter 100, and attracts and retainsmagnetically susceptible particles in the transmission fluid. Themagnetic body 134 is preferably composed of synthetic resin materialhaving magnetic particles dispersed therein, as described in U.S. Pat.No. 6,139,737 (Gizowski), which is herein incorporated by reference.

[0037] Once in the space 136, the transmission fluid then passes throughthe filter media 102 where particles are removed and the fluid filtered.The filtered fluid then collects in central passage 115 and the passage115 directs the fluid to the outlet 111 of hose barb 110, where it exitsthe filter 100.

[0038] In normal forward flow bypass mode (see FIG. 5), if filter media102 becomes plugged during use of filter 100, and the fluid can not passthrough the filter media 102, the differential pressure between inlet108 and outlet 111 overcomes the bias of second spring 131, moving disk129 of rear valve body 122 away from end cap 117, toward aperture 132and compressing second spring 131. This movement of second disk 129allows fluid to pass from front valve body 121 via apertures 125 and138, through rear valve body 122 and apertures 132 and 134, and intocentral passage 115, thereby essentially bypassing filter media 102 (seeFIG. 5, which shows second disk 129 compressing second spring 131). Thefluid then exits through outlet 111 in hose barb 110.

[0039] Thus, although the transmission fluid is unfiltered, the filter100 will not become clogged and back up in the filter 100, causing thetransmission of the vehicle engine to be damaged before it is removed bythe vehicle user.

[0040] However, since the appearance of the inlet tubular hose barb 107and the outlet tubular hose barb 110 of the filter 100 are similar,confusion can occur and the filter 100 can be placed in the transmissionhousing backwards by the vehicle user. In this case, the transmissionfluid enters through “outlet” 111, and passes through central passage115 to reach “inlet” 108 and exit therethrough.

[0041] Thus, in backward or reverse flow (see FIG. 6), the fluid entersin through outlet 111 and passes through central passage 115 to befiltered through the filter media 102. The filtered fluid exiting fromthe filter media 102 enters into the space 136, and flows throughapertures 123 and 127, and out through inlet 108 of hose barb 107.

[0042] However, if the fluid entering through outlet 111 is clogged withparticles, or if filter media 102 is clogged with particles, the abovebackward or reverse flow is difficult to achieve. In conventionalfilters, this would result in a backup within the filter 100, whichwould cause clogging and damage to the vehicle engine transmission.

[0043] However, in the present invention, this clogging during backwardor reverse flow is prevented by the following important structure of thedual direction bypass valve 103.

[0044] In backward or reverse flow bypass mode (see FIG. 7), when thefluid enters the central passage 115 from outlet 111, and the filtermedia 102 is clogged, or the fluid is clogged with particles, and thefluid is unable to be transmitted through the filter media 102, thedifferential pressure around the rear valve body 122 builds up, andovercomes the bias of first spring 127, moving plunger disk 126 of frontvalve body 121 to compress first spring 124. Thus, first disk 126 movesaway from end cap 117, which allows fluid to pass through apertures 133into first retainer 128. The fluid then passes through apertures 123 and127 toward inlet 108, exiting the filter 100. However, second disk 129remains sealed against end cap 117 and does not allow fluid to passthrough aperture 138 in end cap 117.

[0045] Accordingly, the backward or reverse bypass mode allows theunfiltered fluid to pass from central passage 115, through front valvebody 121 and through apertures 133, 123, and 127, towards hose barb 107and “outlet” 108, essentially bypassing filter media 102.

[0046] Thus, again, although filtering of the transmission fluid willnot be achieved in backward or reverse bypass mode, clogging of thefilter 100 will not occur, and the transmission fluid will pass throughthe filter 100, preventing the transmission from overheating anddamaging the vehicle engine.

[0047] Those skilled in the art will recognize that there are othervariations in the preferred embodiment of the present invention, andthat other suitable materials can be used for the various structuralelements of the invention. Further, other attachment techniques, otherthan ultrasonic welding, can be practiced with this invention. Further,the filter can be used for other fluids, such as oil.

[0048] The many features and advantages of the invention are apparentfrom the detailed specification, and thus, it is intended by theappended claims to cover all such features and advantages of theinvention which fall within the true spirits and scope of the invention.Further, since numerous modifications and variations will readily occurto those skilled in the art, it is not desired to limit the invention tothe exact construction and operation illustrated and described, andaccordingly, all suitable modifications and equivalents may be resortedto, falling within the scope of the invention.

What is claimed is:
 1. A dual direction bypass valve for a fluid filter,comprising: a first retainer which houses a first spring at one end, anda first disk disposed at another end of said first spring; and a secondretainer, disposed opposite to said first retainer, said second retainerwhich houses a second spring at one end, and a second disk disposed atanother end of said second spring; wherein said second disk is operativeto compress said second spring in a first direction toward said secondretainer; and wherein said first disk is operative to compress saidfirst spring in a second direction toward said first retainer, saidfirst direction which is opposite to said second direction.
 2. A fluidfilter comprising: an inlet for passage of fluid into said filter; anoutlet for passage of fluid leaving said filter; a filter media disposedbetween said inlet and said outlet, for filtering said fluid; a valvebody comprising: a first retainer which houses a first spring at one endand a first disk disposed at another end of said first spring; and asecond retainer, disposed opposite to said first retainer, said secondretainer which houses a second spring at one end, and a second diskdisposed at another end of said second spring; and an end cap separatingsaid first disk from said second disk; wherein said second disk isoperative to compress said second spring in a first direction towardsaid second retainer; and wherein said first disk is operative tocompress said first spring in a second direction toward said firstretainer, said first direction being opposite to said second direction.3. A fluid filter comprising: a housing defining a chamber, said chamberhaving an inlet at one end through which fluid enters said filter, andan outlet at another end through which said fluid leaves said filter; afilter media disposed in said chamber between said inlet and saidoutlet, for filtering said fluid; means for allowing a fluid to flowfrom said inlet to said outlet in a first fluid flow path, through saidfilter media; forward flow bypass means for allowing said fluid to flowfrom said inlet to said outlet in a second fluid flow path, bypassingsaid filter media; and reverse flow bypass means disposed adjacent saidforward flow bypass means, for allowing said fluid to flow in a thirdfluid flow path, bypassing said filter media.
 4. The fluid filteraccording to claim 3, wherein said first fluid flow path includes saidinlet, a space between an interior face of a central wall of saidchamber and said filter media, said filter media, a central passagewithin said chamber, and said outlet.
 5. The fluid filter according toclaim 3, wherein said means for allowing said fluid to flow in saidfirst fluid flow path comprises: a plurality of apertures in a firstretainer housing a first spring and a first disk, leading to a spacedisposed between an interior face of a central wall of said chamber andsaid filter media; and a central passage within said chamber; whereinsaid fluid passes through said apertures of said first retainer housing,said space, said filter media, and said central passage in said firstfluid flow path.
 6. The fluid filter according to claim 3, wherein saidreverse flow bypass means includes: a front valve body having a firstretainer housing a first spring at one end, and a first disk disposed atanother end of said first spring; and an end cap against which saidfirst disk is seated, said end cap having holes in a periphery of saidend cap which are sealed by said first disk; wherein said first disk isoperative to compress said first spring, moving said first disk fromsaid end cap and opening up said holes for said fluid to pass throughsaid front valve body to said outlet, bypassing said filter media. 7.The fluid filter according to claim 6, wherein said forward flow bypassmeans includes: a rear valve body having a second retainer housing asecond spring at one end, and a second disk disposed at another end ofsaid second spring; wherein said end cap includes a central aperture,and said second disk is disposed against said end cap sealing saidcentral aperture; and wherein said second disk is operative to compresssaid second spring, to allow said fluid to pass through said centralaperture, through said rear valve body to said outlet, bypassing saidfilter media.
 8. The fluid filter according to claim 3, wherein saidsecond fluid flow path leads from said inlet through said front valvebody and through said rear valve body toward said outlet, bypassing saidfilter media.
 9. The filter according to claim 8, wherein said thirdfluid flow path leads from said outlet through said central passage,through said front valve body, to said inlet, bypassing said rear valvebody and said filter media.
 10. The filter according to claim 3, furthercomprising a magnet positioned around a side wall of an interior face ofsaid chamber, which attracts and retains magnetically susceptibleparticles in said fluid.
 11. The filter according to claim 5, furthercomprising a stabilizing spring disposed between said first retainer andsaid housing, said stabilizing spring which holds said first retainer inplace within said chamber.
 12. A fluid filter comprising: a housingdefining a chamber, said chamber having an inlet at one end and anoutlet at another end, through which fluid passes from said inlet tosaid outlet; a filter media disposed between said inlet and said outlet,which filters said fluid; a front valve body having a first retainerhousing a first spring at one end, and a first disk disposed at anotherend of said first spring; an end cap against which said first disk isseated, said end cap having holes in a periphery of said end cap whichare sealed by said first disk, and said end cap having a centralaperture; a rear valve body having a second retainer housing a secondspring at one end, and a second disk disposed at another end of saidsecond spring, said second disk sealing said central aperture of saidend cap; and a stabilizing spring disposed between said first retainerand said housing within said chamber, to hold said front valve bodystably within said chamber; wherein said first disk is operative tocompress said first spring in a first direction, moving said first diskaway from said end cap and opening up said holes in said periphery ofsaid end cap, allowing fluid to pass through said holes and said frontvalve body to exit said filter, bypassing said filter media; and whereinsaid second disk is operative to compress said second spring, to allowsaid fluid to pass through said central aperture of said end cap fromsaid front valve body, through said rear valve body to exit said filter,bypassing said filter media.
 13. A method of preventing clogging of afluid which flows through a filter, comprising: applying a fluid to saidfilter through an inlet; allowing a pressure of said fluid to displace adisk disposed at one end of a spring housed in a retainer of a valvebody, such that said disk compresses said spring; opening an aperture inan end cap against which said disk is seated, by movement of said diskto compress said spring; and allowing said fluid to flow through saidaperture to exit said filter without being filtered by a filter media.14. A method of preventing clogging of a fluid which flows through afilter, said filter which is installed backwards, the method comprising:applying a fluid to said filter through an inlet; allowing a pressure ofsaid fluid to displace a disk disposed at one end of a spring housed ina retainer of a valve body, such that said disk compresses said spring;opening a plurality of apertures in an end cap against which said diskis seated, by movement of said disk to compress said spring; andallowing said fluid to flow through said apertures to exit said filterwithout being filtered by a filter media.
 15. A fluid filter comprising:an inlet for passage of fluid into said filter; an outlet for passage offluid leaving said filter; a filter media disposed between said inletand said outlet, for filtering said fluid; a valve body comprising aretainer which houses a spring at one end and a disk disposed at anotherend of said spring; and an end cap disposed against said disk; whereinsaid disk is operative to move away from said end cap and to compresssaid spring in a direction toward said retainer, allowing fluid to passthrough said retainer, bypassing said filter media, to exit said filter.16. The filter according to claim 15, wherein said end cap comprises acentral aperture and a plurality of peripheral holes.
 17. The filteraccording to claim 16, wherein said valve body is a rear valve body, andwhen said disk compresses said spring, said disk moves away from saidend cap, unsealing said central aperture of said end cap for passage ofsaid fluid therethrough.
 18. The filter according to claim 16, whereinsaid valve body is a front valve body, and when said disk compressessaid spring, said disk moves away from said end cap, unsealing saidperipheral holes of said end cap for passage of said fluid therethrough.19. The filter according to claim 15, wherein said disk is made ofplastic.
 20. The filter according to claim 15, wherein said retainer,said spring, and said end cap, are made of metal.